1) Field of the Invention
The present invention relates to a projector-type headlamp.
2) Description of the Related Art
Conventional headlamps can be found in Japanese Patent No. 2003-338209, Japanese Unexamined Patent Publication No. 2003-7109, Japanese Unexamined Patent Publication No. 2002-197905 and so forth.
These headlamps have a light source, a main reflector and a plurality of subreflectors. When the light source is turned on, the main reflector creates a main light distribution pattern, and the subreflectors effectively utilize a portion of this light, which usually results in becoming ineffective, to thereby creating a sub-light distribution pattern. In this way, the headlamps can effectively utilize the light.
However, most of these conventional headlamps are designed such that the main light distribution pattern and the sub-light distribution pattern overlap, and not configured to irradiate a left outer side and a right outer side, which are dead angles of the main light distribution pattern, thus failing in fully effectively utilizing the light.
An exception is the headlamp disclosed in Japanese Patent No. 3488960. This publication discloses a technique of directing the sub-light distribution pattern to the left side of the main light distribution pattern. Even in this technique, however, only a limited portion of the sub-light distribution pattern is directed to the left side of the main light distribution pattern, and a sufficient luminosity (illuminance and quantity of light) cannot be obtained.
Japanese Patent No. 3488960 also discloses a technique of rotating a subreflector so as to direct the sub-light distribution pattern to the left side or the right side of the main light distribution pattern. However, this technique requires rotating the subreflector in a wide range from left to right, which lowers the efficiency.